The present invention relates to machines such as turbines, and more particularly to a turbine having a rotor and an oil deflector in which the temperature of the rotor near the oil deflector is reduced.
FIGS. 1–3 illustrate a section of a known steam turbine. The steam turbine includes a rotating shaft and an oil deflector. Bearings of the steam turbine provide lubrication oil. While the bearing housing confines much of the lubrication oil, some of the oil leaks and travels axially along the shaft. The oil deflector confines this oil through a plurality of seal rings or “teeth” to allow the oil to be drained.
Due to the relatively high operating temperatures of the steam turbine, oil in the vicinity of the oil deflector may carbonize. In particular, oil within the seal rings is prone to carbonize when subject to high temperatures. The degree of oil carbonization increases with temperature. The carbonized oil is often hard enough to damage the rotating shaft. For example, the carbonized oil is often hard enough to cut grooves in the rotating shaft. While heat shields and the use of lubrication oil as a coolant help control temperature to some degree, they have not been completely successful in preventing oil carbonization at the oil deflector.
It would therefore be beneficial to reduce the temperature of the rotor in the vicinity of the oil deflector to thereby prevent oil carbonization. Damage to the rotor due to oil carbonization can therefore be minimized.